The present invention pertains to machinery for molding compressible powders into specified shapes, and more specifically to molding directly into packages powders used in cleaning and personal hygiene products.
Most commercially available molded products are composed of specified chemicals for a specific purpose, combined with a binder, and sometimes a fluid, and molded at high pressure into tablets. The tablets are then packaged and made available to the public. What is needed is a single integrated method of forming packages of compressed powders in a single apparatus, and the apparatus for implementing the method.
The present invention is an apparatus that receives a mixture of powdered chemicals and preformed thin-walled plastic packaging containers and compresses the powder mixture into the containers at a pressure sufficient to form a solid of the powder yet not so high as to rupture the thin-walled packaging. The preferred apparatus is computer controlled and fully automated, as is the alternative embodiment but manually operated apparatuses are included within the scope of the present invention. Using commercially available components, the apparatus automatically mixes a batch of chemicals in powder form, and transfers the mixture to a hopper. From the hopper the mixture is apportioned volumetrically, or alternatively by weight, where a pre-set volume or weight of the mixture (herein a xe2x80x9cportionxe2x80x9d) is accumulated. The portion is then moved to the inventive forming tool wherein it is placed into the pre-formed packaging and compressed. Further using commercially available components, the package is then moved to a curing station where the portion is allowed to stabilize to one or more pre-determined values such as a unit of time, moisture content, fluid content, hardness, etc. When the desired parameter is achieved, the container is sealed and moved on to another station where it is readied for shipment.
A conventional commercially available forming tool, such as a tableting or molding machine, is improved upon by the present invention. The present invention receives the portion and a preformed thin-walled plastic packaging container, places the portion into the container, and compresses the portion at a pressure generally less than 2000 pounds per square inch (psi), and preferentially in a range of approximately 10 psi to 1000 psi, directly into the container as a mold. The container may have a single cavity or cup, or multiple cups for receiving each portion for compression. Accordingly, the invention includes either a single or multiple press head having at least one upper mold section for accommodating the associated container.
Another embodiment of the forming tool of the present invention comprises a lower mold section for receiving the portion in lieu of the thin-walled container. In this embodiment the lower mold section receives the portion, the press head compresses the portion into the lower mold, then withdraws from the lower mold. The lower mold is then inverted to discharge the compressed portion, which is then transferred to a transport, curing and packaging sequence of machines. The lower mold may be subject to one or more abrupt forces or taps, vibration or an air flow or the like to extract the compressed portion from the lower mold. This embodiment may be operated at pressures greater than 2,000 psi.